Description	Downloads
Lengths Available	2816 Information
Technical Information

Description

The 2817 are racing dampers designed for strut applications.   The 2817 series is a semifinished strut damper where only the mounting brackets need to be added.

The 2817 series uses a "twin guide" installation. The primary guide is fitted to the top of the main cylinder. The secondary guide is fitted to the lowest point of the damper body itself and runs up and down inside the strut housing. Therefore as the strut is compressed, the distance between the two guides increases. This reduces friction and increases strength dramatically under load. Damping adjustments for rebound and compression are made at the bottom of the strut unit.

The 2817 are racing dampers designed for strut applications.   The 2817 series is a semifinished strut damper where only the mounting brackets need to be added.  Some finished applications have been developed and can be found on pages 8 and 9.

The 2817 series uses a "twin guide" installation. The primary guide is fitted to the top of the main cylinder. The secondary guide is fitted to the lowest point of the damper body itself and runs up and down inside the strut housing. Therefore as the strut is compressed, the distance between the two guides increases. This reduces friction and increases strength dramatically under load. Damping adjustments for rebound and compression are made at the bottom of the strut unit.

Bracket Fabrication

The 2817 comes with a steel sleeve of 4.5mm thick which is an integral, yet detachable part of its structure.  Onto this sleeve a bracket can be welded to attach the strut to the upright of the car.  Usually such a bracket will consist of two steel strips, vertically welded parallel to the strut.  The distance between the strips, of course, is equal to the thickness of the upright-fitting flange.  The thickness of the strips should be approximately 5mm.  A TiG welding process is recommended.  Cool the area surrounding the weld and beware of overheating the steel 2817 sleeve.  The resulting distortion will make it difficult to refit the sleeve over the aluminum casing.  If, despite all precautions, the sleeve turns out to be distorted, screw the sleeve onto the casing as far as it will go and then tap around the circumference of the sleeve with a soft faced hammer until the sleeve is free to move.

Droop Limiter

A droop limiter can be installed to reduce L max.  The limiter length can be increased in steps of 5mm and can be changed by a KONI service center.  Please state the required length at the time of ordering. 

Disclaimer; At full droop the beam strength of a strut assembly is at its minimum.  To warrant sufficient strength and safe operation, a droop limiter is usually installed inside the damper.  Unfortunately, the resulting dimensions of the damper do not allow for the combination of a very low ride height and sufficient clearance to remove the wheels when the car is on jacks.  As a solution, the droop limiter is sometimes shortened or removed.  As a result, the damper can potentially be used outside of its safe operation limits.  Under NO circumstance should a dynamic load be allowed to act on the strut assembly when the dampers are at such extended droop.

 

2816 Series Information

The 2816 is a damper for use in strut housings that are designed and fabricated by the customer.  The damper is to be used in an inverted “twin guide” installation. 

 Components Supplied by KONI

*  Fully assembled piston rod attachment, containing the adjuster assembly

*  Primary guide bushing and the secondary guide PTFE ring.

*  Lock nut with integrated dirt scraper.

 

 2816 Strut Housing Fabrication

All dimensional and finish requirements of the damper strut housing are noted in the drawing to the right.  For the inside of the cylinder, it is important to achieve the small tolerance and smooth surface finish.  Both are vital for low friction and durability

Lengths Available

	L max	L max	L min	Stroke	L cylinder
Length Code	Dynamic*	Static**		Max
2817A43 VVV 00	429	429	310	119	251
2817A47 VVV 00	469	469	330	139	271
2817A51 VVV 00	509	509	350	159	291
2817A55 VVV 25	549	549	370	179	311
2817A59 VVV 25	589	589	390	199	331

Note:  

*        This is the max length allowed under dynamic conditions.

**      The damper should only reach this length under static (no load) conditions.

Technical Information

How to determine the required damper lengths for the 2817/2816

For the following setup, it is assumed that the car is already equipped with dampers.

1.  Put the car on a flat level surface.  Measure the distance between the upper and lower spring seats.

2        Jack the car up to maximum desired droop.  Measure the distance between the upper and lower spring seats.

3        Support the car on jack stands.  Remove the wheels, springs and bump rubbers.  For convenience, disconnect the sway bars if possible.

4        Now raise the suspension to the point where either the cassis would hit the ground or a suspension component uses up all its available travel.  If the factory length struts are being used for measuring, it is necessary to determine if the length of the strut housing will require shortening to achieve the desired bump travel.

5        Subtracting the value found at Step 4 with the value found at Step 2 give the required stroke.

6        Find a 2817/2816 that has this required stroke.  Not its L min.

7        Check that this L min fits within the dimension found at Step 4.

8        If the L min is too long, check the next shorter length and determine if the L max will be sufficient.

9        If the L min is too short, check the next longer length.  The L max can be shortened by increasing the length of the internal droop limiter of the damper.

 

Downloads

28-series Build Manual Metric Units
28-series Build Manual English Units